Due to forces exerted on a workpiece, the worktable and workpiece supporting structures of such machines, distortions and misalignments occur. These result in inaccuracies in the dimensions and shape of the final machined article.
Where the dimensional errors are of the same order as the accuracy to which the article is to be machined it is impossible reliably to machine the article.
Distortions misalignments and other error producing effects which can arise amd tend to be cumulative must therefore be reduced to a level which is such that the magnitude of the cummulative error in the final article is much less than the error which can be permitted therein.
One of the primary controlling parameters in a machining operation is the accuracy with which the workpiece position relative to a machining tool is known. This parameter has been addressed and solutions proposed in our co-pending applications No (our references C421.01/L, C422.01/L,) filed concurrently herewith.
It is an object of the present invention to provide a system and method of operation of such a machine by which complex shapes and forms can be machined (typically by way of grinding) thereby to take advantage of the high accuracy now available when using such a machine.
The invention is of particular relevance to a cylindrical grinding machine.